TALES OF THE TRIBUTARIES

With the Helmsdale’s pristine conditions making for easy spectating, Michael Wigan witnessed the fascinating cycles of spawning salmon up close

Michael Wigan has witnessed the fascinating cycles of spawning salmon along the Helmsdale

This year is matchless for watching spawning salmon and trout. The water is low and clear. A spectator can view nature, close-up, in dramatic reproductive action, the fish imperturbable in completion of their cycle.

The first signs of the presence of migratory fish in the higher tributaries of the Helmsdale were about four days into November. I waited in a truck on a high bank with a view straight downstream. Nothing happened. The black water tinkled and rolled gently to the sea 20 miles away. Then a bulge showed in the fast water. The spine of a fish rose and sank.

He wriggled up determinedly through scattered stones, picking the deepest channel before rapidly mounting the stony shallows. Then he ran out of water, momentarily, and three quarters of his black body showed, twisting in the air. A moment later he was thrusting forward again to the next deep pool for shade and cover.

It was just before dark. Full daylight would be too risky to move. A woodcock flown under the full moon from Scandinavia whizzed by. A few days earlier fish were in the tails of the pools. They had progressed into the oxygenated currents. Next, the redds, where they pair up.

And so it was. Three days later, uncaring of stark figures on the skyline, pairs assembled side by side. Below water she would be cutting redds with sweeps of her tail and squirting ova into them, moving forward and filling them, like sauce into a roll, extrusions of the next generation of silver salmon. The cock would move sideways and cover them with milt, depositing his hereditary bequest on the hen salmon of his choice.

American researchers report that in some rivers precocious male parr, which nip in if opportunity occurs, account for a third of all ova successfully fertilised. It is astonishing, surely, that a fish a few inches long has the same potency as an adult male salmon. Maybe more. For the biggest males are often barely fertile.

Two days later there was a different scene. Energy had drained from the drama. Fish were moving, but this time downriver. They faced downstream and allowed the water to carry them, curving and feebly twisting through the same stones they struggled days earlier to pass. After a stony section one turned and faced the current, inhaling oxygen from the flow. Again, it was gathering dark, reducing predation risk.

This year a strange thing occurred. One salmon, following rain, jumped a waterfall on a tributary even higher up, way back in mid-October. He stationed himself at a faraway junction waiting for female company. He found company, but not of a mate. The early-spawning salmon was dragged onto the bank with half his head eaten off. The otter got there first. The otter is the primary predator for spawners in this place. Early running salmon run the otter gauntlet to spawn earlier, give their eggs a chance to hatch and become fry sooner, and out-compete their colleagues seeking out available invertebrates in the burns.

The trout reproductive story had taken place a few days earlier. Trout had colonised a new gravel and silt outwash from a landslide. Hundreds of yards of new mobile habitat provided egg receptacles waiting to be filled.

Trout have a different enemy, the heron. Behaviour is styled accordingly. If you walk anywhere near they see you and dart under shady banks not to reappear. Watching spawning trout involves getting almost horizontal to avoid being seen.

The heron, a specialist, can stalk a burn, immobilise himself, and fill his gullet every fifty yards or so.

It is common knowledge that thousands of ova turn into just a few surviving fish. The rest are the smorgasbord for otter and heron. As winter draws in the spawning spectacle is promise that spring heralds new life and another generation of occupants in the streams. Salmon colonised the British Isles longer ago than man did.

Their evolution is a step or two ahead.

“Early running salmon run the otter gauntlet to spawn, giving their eggs a chance to hatch